Mario has 300 seconds on the timer to complete this level, and it consists mainly of an underground area, where Lava becomes a hazard early in the stage. If Mario completes this level, he gains access to Wendy's Castle, skipping most of the levels in Chocolate Island.

Mario begins the level near a spring on top of an Block right above the lava, where a Blargg waits, hidden in the lava, to attack Mario when he approaches the spring. The level starts out already dangerous, as Mario can fall in the lava if he keeps going to the right. A corridor with two Buzzy Beetles follow this and as Mario crosses this corridor, he is attacked by Chargin' Chucks, kicking footballs at him. Dodging these dangerous enemies and avoiding Bottomless Pits, Mario must continue through the level, eventually finding a ? Block containing either a Super Mushroom or a Cape, depending on the plumber's current form. Nearby the ? Block is a green Warp Pipe. This pipe leads to an above-ground area with an Amazing Flyin' Hammer Brother and falling Platforms over a Bottomless Pit. At the end of that area is a yellow Warp Pipe that leads back down into the main underground area. Another Chargin' Chuck attacks the plumber with footballs, as he approaches a green Warp Pipe. Mario can find the Midway Gate of the level once he passes through an area with two Chargin' Chucks.

The nearby green Warp Pipe brings Mario to the second area of the cavern, where he can defeat several Buzzy Beetles by sliding down the slopes and avoiding a small pit with a few Munchers, to the bottom of the cavern, where another green Warp Pipe takes Mario to a dangerous area with Spike Tops, and yellow platforms bobbing in the lava. Once Mario steps these platforms, they start to sink in the lava, forcing the hero to run and jump from platform to platform until he reaches solid ground. Several Chargin' Chuck appear here, as well as a ? Block. Mario eventually finds another row of yellow platforms in the lava, leading the hero to the only Dragon Coin of the level. Ahead of this area is a Warp Pipe that leads Mario to the Goal Gate.